1. Field
The described technology relates generally to a liquid crystal display (LCD) and a manufacturing method thereof.
2. Description
Currently, various flat panel displays are being developed. Among them, a liquid crystal display is widely used as a flat panel display.
Liquid crystal displays (LCDs) are classified into a TN (twisted nematic) type, a VA (vertically aligned) type, an IPS (in plane switching) type, an ECB (electrically controlled birefringence) type, a PLS (plane to line switching) type, an FFS (fringe field switching) type, or other types according to an arrangement state and driving method of the liquid crystal. Regarding the liquid crystal displays, liquid crystal is initially arranged in a predetermined manner because of the influence of an alignment layer or characteristics of the liquid crystal, and when an electric field is applied, the liquid crystal is arranged in another (or different) manner such that the polarization state of light that passes through the liquid crystal becomes differentiated according to the arrangement state of the liquid crystal due to optical anisotropy of the liquid crystal, and the differentiation is displayed as a difference of (or change in) the amount of transmitted light by using (or through) a polarizer, thereby displaying an image.
Among the types of liquid crystal displays, the liquid crystal display (LCD) of the TN type, the IPS type, the ECB type, the PLS type, and the FFS type can be classified as being a horizontal type because the liquid crystal is initially aligned horizontally, an upper alignment layer and a lower alignment layer to determine (or control) the alignment direction of the liquid crystal are respectively formed at an upper substrate and a lower substrate, the upper alignment layer and the lower alignment layer are respectively rubbed, and then liquid crystal is injected to form the liquid crystal layer.
However, various protrusions causing steps (or non-uniformities) exist on the lower substrate or the upper substrate such that texture due to non-uniformity of rubbing strength and abrasion non-uniformity of a rubber are generated in the liquid crystal display (LCD) when performing the rubbing process under the existence of the steps, and thereby optical characteristics such as transmittance and contrast ratio are deteriorated.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.